The present invention concerns a coating agent composition which has a rapid curing rate, and which can form a cured coating film that is superior in terms of water resistance, anti-static properties and gas barrier properties following curing, and a composite film which is formed by laminating a cured film of said coating agent composition.
It is known that composite films having superior gas barrier properties are obtained by coating an organic resin film with a composition consisting chiefly of an organosilane. Examples of such compositions include compositions consisting of tetramethyl orthosilicate, an alkoxysilane such as a vinyltrialkoxysilane and a polyvinyl alcohol (see Japanese Patent Application Kokai No.6-329821), and mixtures which consist of an amino-group-containingalkoxysilane and a compound which contains aromatic rings such as xylylene diisocyanate (see Japanese Patent Application Kokai No. 7-18221). Furthermore, a method is also known in which a packaging material with superior gas barrier properties is obtained by coating an organic resin film with vinylbenzyl(2-aminoethyl)-3-aminopropyltrimethoxysilane and curing this coating film by irradiation with high-energy radiation (see Japanese Patent Application Kokoku No. 5-73774). However, the compositions used in these methods all suffer from the drawback of a slow curing rate. Furthermore, the cured films obtained following curing have inferior water resistance, and show a drop in performance under conditions of high humidity.
It is an object of the present invention to provide a coating agent composition which has a rapid curing rate, and which can form a cured coating film that is superior in terms of water resistance, anti-static properties and gas barrier properties following curing, and a composite film which is formed by laminating a cured coating film of said coating agent composition.
The present invention provides a high-energy radiation curable coating agent composition which comprises (A) an amino-group-containingalkoxysilane, such as N-xcex2-(N-vinylbenzylaminoethyl)-xcex3-aminopropyltrimethoxysilane, which can be expressed by the general formula 
wherein R1 and R2 are divalent hydrocarbon groups with 12 or fewer carbon atoms, R3 is an alkyl group with 6 or fewer carbon atoms, a cycloalkyl group or a phenyl group, and R4 is a hydrolyzable group selected from a set consisting of alkoxy groups and aryloxy groups, Q1, Q2 and Q3 are selected from the group consisting of hydrogen atoms and groups which can be expressed by the general formula Xxe2x80x94C6H4xe2x80x94CH2xe2x80x94 wherein X is a vinyl group or a hydrogen atom, with the proviso that at least one of said Q1, Q2 and Q3 groups are a group expressed by the general formula Xxe2x80x94C6H4xe2x80x94CH2, n is 0, 1 or 2, and a is 0, 1 or 2, or a hydrochloride of the same, and (B) an organic compound which can be expressed by the general formula 
wherein R5 is a residue of an organic polyhydric alcohol containing alcoholic hydroxyl groups bonded to different carbon atoms, or a residue of an ester formed by such an organic polyhydric alcohol and a polybasic acid, R6 is a hydrogen atom or a methyl group, and b is an integer from 2 to 6. Also in accordance with the present invention, a composite film is formed by laminating a cured coating film of the above-mentioned coating agent composition on at least one side of an organic resin film.
In the above general formula which describes (A), R1 indicates a divalent hydrocarbon group which has 12 or fewer carbon atoms, e.g., an alkylene group such as a methylene group, ethylene group or propylene group, etc.; in particular, an ethylene group is especially desirable. R2 indicates a divalent hydrocarbon group which has 12 or fewer carbon atoms, e.g., an alkylene group such as a methylene group, ethylene group or propylene group, etc., or an arylene group such as a phenylene group or tolylene group, etc.; in particular, a propylene group is especially desirable. R3 indicates an alkyl group with 6 or fewer carbon atoms, a cycloalkyl group or a phenyl group; in particular, a methyl group is especially desirable. R4 indicates a hydrolyzable group selected from a set consisting of alkoxy groups and aryloxy groups, e.g., methoxy groups, ethoxy groups and phenoxy groups; in particular, a methoxy group is especially desirable. Q1, Q2 and Q3 indicate groups which can be expressed by the general formula Xxe2x80x94C6H4xe2x80x94CH2xe2x80x94 (in the preceding formula, X indicates a vinyl group or a hydrogen atom, with a vinyl group being especially desirable) or hydrogen atoms, with at least one of said groups being a group expressed by the general formula Xxe2x80x94C6H4xe2x80x94CH2xe2x80x94 (in the preceding formula, X is the same as described above), n is 0, 1 or 2, and is preferably 1, a is 0,1 or 2, and is preferably 0.
Concrete examples of component (A) include N-xcex2-(N-vinylbenzyl-N-benzyl)aminoethyl-xcex3-aminopropyltrimethoxysilane or a hydrochloride of the same, N-xcex2-N-vinylbenzylaminoethyl)-N-benzyl-xcex3-aminopropyltrimethoxysilane or a hydrochloride of the same, N-xcex2-(N-vinylbenzyl-N-benzyl)aminoethyl-N-benzyl-xcex3-aminopropyltrimethoxysilane or a hydrochloride of the same, N-vinylbenzyl-N-benzyl-xcex3-aminopropyltrimethoxysilane or a hydrochloride of the same, N-xcex2-N-vinylbenzyl-N-benzyl)aminoethyl-N-benzyl-xcex3-aminopropyltriethoxysilane or a hydrochloride of the same, N-xcex2-(Nvinylbenzyl-N-benzyl)aminoethyl-N-benzyl-xcex3-aminopropylmethyl-dimethoxysilane or a hycholride of the same, N-xcex2-(N-vinylbenzyl-N-benzyl-xcex3-aminopropylmethyl-dimethoxysilane or a hydrochloride of the same, N-xcex2-(N-vinylbenzyl-N-benzyl)aminoethyl-N-benzyl-xcex3-aminopropylmethoxydimethylsilane or a hydrochloride of the same, N-xcex2-(N-vinylbenzyl-N-benzyl)aminoethyl-N-benzyl-xcex3-aminobutyltrimethoxysilane or a hydrochloride of the same, N-xcex2-(N-vinylbenzyl-N-benzyl) aminoethyl-N-benzyl-xcex3-aminopentyltrimethoxysilane or a hydrochloride of the same, and N-xcex2-(N-vinylbenzyl-N-benzyl)aminoethyl-N-benzyl-xcex3-aminohexyl-trimethoxysilane or a hydrochloride of the same, etc. In cases where a high-viscosity compound is used, the compound may be diluted with a solvent prior to use. Examples of solvents which can be used include methanol, ethanol, 1-propanol, 2-propanol, toluene, xylene, hexane, 1,1,1-trichloroethane,n-butanol and dioxane, etc.
In the above general formula which describes (B), R5 indicates a residue of an organic polyhydric alcohol containing alcoholic hydroxyl groups bonded to different carbon atoms, or a residue of an ester formed by such an organic polyhydric alcohol and a polybasic acid. Examples of such polyhydric alcohols include ethylene glycol, polyethylene glycols with a degree of polymerization of 2 to 30, propylene glycol, polypropylene glycols with a degree of polymerization of 2 to 30, 2,2,4-trimethyl-1,3-pentanediol,1,4-cyclohexanedimethanol,2,2-bis[4-(2-hydroxyethoxy)phenyl]propane,2,2-bis[4-(2-hydroxypropoxy)phenyl]propane,2,2-bis(4-hydroxyphenyl)propane,2,2-bis(4-hydroxycyclo-hexyl)propane,1,6-hexanediol, 1,5-pentadiol [sic], 2-ethyl-1,3-hexanediol, glycerol, trimethylolpropane and 1,2,6-hexanetriol, etc. Furthermore, examples of the above-mentioned poly basic acids include phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, terephthalic acid, adipic acid, sebacic acid, maleic acid and fumaric acid, etc. Concrete examples of such organic compounds include diethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropanetriacrylate, pentaerythritol tetraacrylate and trimethylolpropanetrimethacrylate, etc.
It is desirable that the amount of component (B) that is used in the composition of the invention, be 1 to 10,000 parts by weight (preferably 50 to 2,000 parts by weight) per 100 parts by weight of component (A). In cases where the amount of component (B) that is added exceeds 10,000 parts by weight, there is a possibility that performance values of the cured product such as anti-static properties and gas barrier properties, etc., will be lost. On the other hand, if the amount added is less than 1 part by weight, curing is retarded so that the composition lacks practicality.
The coating agent composition of the present invention can easily be manufactured by uniformly mixing the above-mentioned component (A) and component (B). If necessary, various types of additives, the use of which in coating agent compositions is universally known, may generally be added to the coating agent composition of the present invention in addition to the above-mentioned components, as long as the addition of such additives does not interfere with the object of the present invention. Examples of such additives include silane coupling agents, pigments, antioxidants, agents which improve adhesion to the substrate, and agents which prevent thermal polymerization, etc. Examples of silane coupling agents which can be used include xcex3-aminopropyltrimethoxysilane, xcex3-aminopropyltrimethoxysilane[sic], tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, vinyltri-methoxysilane, xcex3-glycidoxypropyltrimethoxysilane, xcex3-glycidoxypropyltrimethoxysilane, xcex3-methacryloxypropyl-trimethoxysilane, xcex3-chloropropyltrimethoxysilaneand xcex3-mercaptopropyltrimethoxysilane, etc.
After being applied to various types of substrates, the coating agent composition of the present invention is cured by being irradiated with high-energy radiation such as ultraviolet light, X-rays or an electron beam, etc. The thickness of the cured coating film of the composition of the present invention can generally be set at approximately 1 micron to 1000 microns. Substrates which can be used include organic resin films such as polyethylene films, polypropylene films and polyethylene terephthalate films, etc., as well as metal and glass, etc. Among these materials, organic resin films are especially desirable.
Known methods may be used to apply the coating agent composition of the present invention to the substrate e.g., a method using a coater such as a knife coater or roll coater, etc., or a method using spraying or immersion, etc.
The coating agent composition of the present invention described above has a rapid curing rate, and forms a cured film which has superior water resistance, anti-static properties and gas barrier properties, etc., following curing. Furthermore, films formed by laminating a cured coating film of the composition of the invention on at least one side of an organic resin film are superior in terms of water resistance, anti-static properties and gas barrier properties, etc., and can therefore be used in applications in which such characteristics are required.
Below, the present invention is described in terms of practical examples of application. Furthermore, in the practical examples, curability, curing time and water resistance were evaluated as follows:
Curability, Curing Time
The coating composition was applied as a coating to the surface of an organic resin film, and was cured by irradiation with ultraviolet light for a prescribed period of time. Afterward, the surface of the cured coating film was rubbed five times with the fingers in order to ascertain whether sufficient curing had occurred. The time after which smudging no longer occurred in the cured coating film, and the cured coating film was no longer stripped from the surface of the organic resin film, was taken as the curing time.
Water Resistance
The coating composition was applied as a coating to the surface of an organic resin film, and was cured by irradiation with ultraviolet light. Afterward, the composite film (2 cmxc3x975 cm) thus obtained was immersed in a 100-cc beaker containing 50 cc of ion exchange water, and was allowed to stand for a prescribed period of time. The composite film was then removed, and the surface of the composite film was wiped clean by being rubbed five times with a paper cloth. The evaluation results were expressed as follows:
O: No swelling or variation was seen in the cured coating film, and the cured coating film was not stripped from the organic resin film.
X: The cured coating film was stripped from the surface of the organic resin film.